The present proposal is the continuation of the annual follow-up of a cohort of children aged 5-9 years and their family members. The objective of the study is to identify risk factors for obstructive airways disease which operate early in life. To date it has been determined that: 1) "high" risk families, as defined in this study, have lower levels of pulmonary function than other families. 2) Parents' cigarette smoking is associated with both a lowered level of pulmonary function and an increased prevalence of wheezing in their children. 3) childhood respiratory illness appears to have limited impact on levels of pulmonary function in children in this study. 4) There is a very high year-to-year correlation in age, sex, height standardized pulmonary function in children suggesting that some children with relatively impaired pulmonary function are not likely to outgrow their lowered levels of function. In the coming year continued screening of the cohort will occur. Analysis will focus on factors influencing the changes in level of function in growing children.